Graphite is a hexagonal layer compound of SP2 carbon and a layer constituting graphite is called graphene. Previously, a method of heat-treating silicon carbide and a method of layering graphene on a metal film such as a copper foil by the CVD method have been known for obtaining graphene.
On the other hand, a method has been known in which graphite is treated with a strong acid to dope ions between graphite layers and is further rapidly heat-treated to obtain graphene oxide or exfoliated graphite which is more reduced in the number of graphene layers than original graphite (Patent Literature 1 described below).
Also previously, various studies have been made as to composite materials of a polymer and exfoliated graphite obtained by a treatment of exfoliating graphite. For example, the following Non-Patent Literature 1 reports that when a polymerization initiator and a styrene monomer component are mixed in the coexistence of exfoliated graphite obtained by a treatment of exfoliating graphite based on chemical treatment to polymerize the monomers, a styrene polymer chain is grafted onto the surface of graphene.